Bibliographic citations and references
Bibliographic or other citations may be found gathered together in a bibliography or list of references as a separate part of a running text, possibly with embedded narrative or discussion. They may also appear embedded within a running text, either in full or in abbreviated form. In either case, the parts of the citations are conventionally marked off from each other and from the flow of text by such features as bracketting, italicising, underlining etc. It is clearly necessary to distinguish the component parts of a citation for retrieval purposes - to distinguish London as an author's name from London as a place of publication or in a title, for example.
Collections of bibliographic citations which do not form part of running text should be identified by a list.citn tag. Each citation within such a group (or within the body of a text) should be identified by a citn tag, or a citn.struct tag if its content is organised in a particular way. In either case, different component parts should be identified by the appropriate tag from those specified below (section ); in the latter case, they must be so identified.

Internal structure of citations
The following commonly occurring component elements of citations should be distinguished where possible. If embdedded in a citn.struct , they must be distinguished, but their order is not important. Not all of them need be present in every case. A citn may however have no substructure at all. author Primary statement of responsibility for bibliographic work. May include several names, or an institutional name. editor Secondary statement of responsibility (e.g. editor or compiler; an attribute `role' may be used to distinguish these) title Title of monographic work title.piece A specific or secondary title (e.g. of a journal article or a part within a collection) series Title of a series of publications publisher Name of a publisher or other agency publ.city Place of publication publ.date Date of publication imprint Additional information about the imprint citn.detail Page numbers, section etc. comment Any additional comment on the item e.g. an abstract or brief note about it.

Citation references
Citations embedded within a text or list are most easily dealt with when they take the form of short references such as [Nelson, 80] or footnotes. These placeholders are like footnotes or other cross-references in the body of the text, except that the same placeholder may be used repeatedly throughout a text, and that they are often further qualified: [NEL80, especially p1020] for example. Provided that the text contains somewhere a full bibliographic list, as described in above, then the tag citn.ref should be used to identify the placeholder. This tag always has an ID attribute which identifies the target of the reference by supplying the value of the ID attribute in the corresponding element within the cit.list.
The actual value for the ID may not be the same as that in the text: for example, it may say ibid or Nelson 1980 in the text, but NEL80 in the bibliography. The actual formulation used in the text may also modify the reference in some way, for example by supplying a page number. An optional attribute, `form' may be used to cover both of these cases. If supplied, its value gives the actual form of the reference found in the text. is this wise? should it be an element?